Boiler-tube ferrule



Patented Oct. 4, I898.

N0. 6ll,959.

G. W. DUVALL.

BOILER TUBE FERRULE.

(Application filed Max. 4, 1896.)

(No Model.)

GEORGE W. DUVALL, OF NORFOLK, VIRGINIA.

BOILER-=TUBE FERRULE.

SPECIFICATION forming part of Letters Patent No. 611,959, dated October4, 1 898.

Application filed March 4, 1896.

To all whom it may concern.-

Be it known that I, GEORGE W. DUVALL, a citizen of the United States,residing at Norfolk, in the county of Norfolk and State of Virginia,have invented certain'new and useful Improvements in Boiler-TubeFerrules; and I do hereby declare the following to be a full, clear, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same, referencebeing had to the accompanying drawings, and to letters of referencemarked thereon, which form a part of this specification.

The object of the present invention is to provide better means than haveheretofore been employed for preventing boiler-tubes from leaking andfor closing such leaks when they occur at the junction of the tubes withthe tube-sheet, and itis particularly designed to be an improvement uponthe ferrule and key for which Letters Patent of the United States No.54,703 were issued to me May 15, 1866, and Letters Patent No. 240,818May 3, 1881.

In the ferrules illustrated in both of the said patents it will beobserved that the tube forms the backing for the key when it is drivenin, and thus it exerts great pressure on the tube as well as on thesplit ferrule. Consequently on hard driving it is apt to split the tube.In the present case I overcome this defect by forming the ferrule andkey with interfitting edges constituting guideways for the key-wedge.The key conforms in curvature to the cylindrical ferrule and forms awedge-section thereof and by which it is supported and held. Thus thekey is entirely free from the tube while it is being driven home, andthough completing the circle of the ferrule and protecting any Weak spotin the tube opposed thereto it cannot bind against the tube while it isbeing driven and split it. Then, again, as the key does not bind againstthe tube it allows a close fit of the ferrule to the tube. It is wellknown that when the end of a boiler-tube is attached to the flue-sheetit becomes larger from the action of the rolling-tool, and the ferruleis made with an enlargement of its diameter just below the flange toconform to the enlarged end of the flue.

Serial No. 581,837. (No model.)

In the drawings, Figure l is a face View of a ferrule fitted into aboiler-flue without the key, Fig. 2 is a longitudinal section on theline 2 2, the same showing the key in place. Fig. 3 is a transversesection through the tube, ferrule, and key on the line 3 3, Fig. 2; andFig. 4 is a detached View of the key.

A is a tubular ferrule made with the curved flange B to fit over thebeaded end of the tube 0 and against the face of the tube-sheet D, thesaid flange having one or more slots 1) inaddition to the cut I),contiguous to the key-seat A. The ferrule is'formed with the swell orenlargement at a, conforming to the expanded end of a tube O.-

The key-Wedge E is preferably curved to conform to the radius oftheferrule, and it has its side edges e c rounded, the same engagingwith the grooved ways c in the sides of the key-seat. The guideways abeing formed by grooving out the edges of the walls of the slot 1),retaining lips or edges are produced, which hold the key in positionwithin the guideways and prevent it from slipping out laterally. This isimportant, as it avoids any liability of the key being driven out of astraight course and coming in contact with the inner surface of theboiler-tube. By this construction of guideways it is manifest that thewedge-shaped key can only be inserted from the flange end of theferrule. The grooved way is centrally located in the metal constitutingthe ferrule, so that when the key is entered therein it will not projectbeyond the edges of the key-seat, but will be flush therewith, so thatit will not impinge against the inner wall of the tube while beingdriven in. I regard this as an important feature of my invention, aswith my former construction the key came in contact with the inner wallof the tube, and in some instances where the tube was weak it was brokenduring the driving action. I experienced these difficulties with myformer constructions, and as a result of considerable thought andexperiment devised this improved construction. These guideways may ofcourse be angular or otherwise formed, so that the key-Wedge engageswith and slides in the ferrule and is held by the same.

Upon an examination of Fig. 4 of the drawings it will be seen that thekey has four curved surfaces and two beveled surfaces, while in myformer patents the key is merely wedge-shaped and has no curvedsurfaces. With my new construction of key and by providing the groovedways in the ferrule for the key to slide in one blow has the effect ofthree blows on the old construction of key. The ways retain the key andguide it perfectly during the driving action, so that it cannot possiblycome in contact with the inside of the tube.

To apply a ferrule to a boiler-tube, the ferrule is inserted into theend of the tube, after first applying thereto red lead or other suitablesubstance to the end of the tube, and the key is driven home, expandingthe ferrule uniformly against the interior surface of the tube aroundthe entire circumference without any binding or excess of pressure alongthe line of the key. Consequently not only the tube is not injured bythe key, but it requires fewer blows to seat it.

What I claim is 1. A split hollow-tube ferrule having a flange andprovided with a longitudinallyarranged slot for the reception of a key,the walls of the slot being provided with longitudinal guideways, and awedge-shaped key which is entered into the ways from the flange end ofthe ferrule and is confined and guided by said ways, the outer surfaceof the key when the key is in position within the slot, being flush withthe outer surface of the ferrule, substantially as described.

2. A split. hollow-tube ferrule having a flange provided with a curvedunder surface which receives the bead on the outer end of theboiler-tube, said ferrule being provided with a longitudinally-arrangedslot for the reception of a key, the walls of the said slot beingprovided with longitudinal, grooved guideways, having retaining edges,and a wedge-shaped key which is curved in crosssection to conform to thecurvature of the ferrule, which key is entered into the ways from theflange end of the ferrule and is retained and guided by said ways, thekey being confined within the guideways so as not to project beyond theouter surface of the ferrule, substantially as described.

3. A split boiler-tube ferrule having a flange provided with a curvedunder surface which receives the bead of the outer end of theboiler-tube, said ferrule being thickened or enlarged all around at apoint adjoining the flange, to conform to the expanded end of theboiler-tube, and also provided with a longitudinally-arranged slot,which extends through the flange of the ferrule for the reception of akey, the walls of the said slot being provided with longitudinalguideways and a wedge-shaped key which is entered into the ways from theflange end of the ferrule and is confined and guided by said ways, so asnot to come in contact with the inner surface of the boiler-tube whenbeing driven in, substantially as described.

4. A split hollow-tube ferrule having a flange provided with alongitudinally-arranged slot for the reception of a key, the walls ofthe slot being provided with longitudinal guideways, and a wedge-shapedkey which is curved in crosssection to conform to the curvature of theferrule, the said key being entered into the ways from the flange end ofthe ferrule and retained and guided by said ways, the key fallingentirely within the metal constituting the ferrule so as not to projectbeyond the inner surface of the same and come in contact with the innersurface of the boiler-tube when being driven in, substantially asdescribed.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE W. DUVALL. lVitnesses:

WILLIAM II. TABB, JAMES M. ALEXANDER.

